Is this really necessary? Same Concrete supplier....one pile from Friday and one Saturday...is their job really that difficult? 

Mixer driver or testor ? Driver on the cell phone doing the facebook shit and a testor to lazy to use a shovel for a sample .

use a tarp , or a small piece of sign material to make it slide back on their feet , they'll get right

Drivers. There was one guy...only one backed up to the pump. I was literally five feet from him...hadn't even idled the truck up...over flows the hopper. I just walked away cause I wulda got myself in trouble. And that's a good idea Beast..or accidently not here my horn beat lol but if I do that then I'll get air in the pipes so maybe I'll try the tarp.